AB1243 WHICH IS THE MOST APPROPRIATE SONOGRAPHIC DEFINITION FOR ASYMPTOMATIC HYPERURICEMIA WITH MSU CRYSTAL DEPOSITION?
Authors: M. L. Peral, S. Gomez-Sabater, R. Caño-Alameda, A. Bermúdez-García, T. Lozano, R. Sánchez-Ortiga, M. Perdiguero, E. Caro, C. Ruiz, R. Francés, E. Pascual, M. Andrés
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Cumulative data indicates that 20-30% of subjects with asymptomatic hyperuricemia (AH) have silent monosodium urate (MSU) crystal deposition<sup>[1]</sup>. For its evaluation, several sonographic examination schemes have been used<sup>[2]</sup>, and the scanning of the 1st metatarsophalangeal (MTP) joint and femoral condyle for double contour (DC) sign, plus 1st MTP for tophi, shows the highest prevalence and discrimination compared to subjects with normouricemia. However, how we should sonographically classify AH with crystal deposits remains to be defined. <h3>Objectives</h3> To compare the variations in prevalence of sonographic deposits in AH across different classification schemes. <h3>Methods</h3> Observational, cross-sectional study. Patients with AH were consecutively recruited from clinics and wards of internal medicine, cardiology, nephrology, endocrinology, rheumatology and primary care units in an academic center. Subjects with a recent serum urate level ≥7mg/dL were included, excluding those under urate-lowering therapy and/or colchicine or with gout or other inflammatory rheumatic disease. Ultrasound was performed by an expert rheumatologist sonographer, blinded to clinical and laboratory data, following 2021 OMERACT definitions for elementary gout lesions (DC sign, tophi, aggregates) and 0-3 grading<sup>[3]</sup>. The locations scanned bilaterally were knees with patellar tendons, ankles with Achilles' tendons, and 1st and 2nd MTP joints. We applied different definitions for AH with deposits, varying in relation to deposits (any deposits; only DC sign and/or tophi; only grade 2-3 deposits; only grade 2-3 DC sign and/or tophi) or locations (10 locations; reduced 4-joint scheme including knees and 1MTPs; more than 1 location with deposits). Comparisons were performed by Chi2 test. <h3>Results</h3> Seventy-seven participants with AH were studied, 55 males (71.4%) and a mean age of 59.8 years (SD 17.3). Mean body mass index was 31.2 kg/m2 (SD 5.2), and 37.66% and 29.9% suffered from cardiovascular and chronic kidney disease, respectively. Mean uricemia was 7.6 mg/dL (SD 1.6) with a fractional excretion of uric acid of 5.6% (DS 2.2). Regarding the elementary lesions, the median (p25-75) number of locations with DC sign, tophi or aggregates was 0 (0-1), 1 (0-2) and 1 (1-2), respectively. For grade 2-3 lesions, numbers were 0 (0-0), 1 (0-1) and 1 (0-2), respectively. As shown in <b>Figure 1</b>, the proportions of sonographic deposits largely varied according to the different classifications considered to define AH with deposits, ranging from 23.38% up to 87.01%, in a significant manner (p&lt;0.050). <h3>Conclusion</h3> In a multidisciplinary sample of AH, the rates of sonographic deposits dramatically varied across the different classifications used, highlighting the need for an agreed and validated definition that facilitates further research in this setting. <h3>References:</h3> <i>[1] Bengana B, et al. Rev Rhumat. 2022; doi: 10.1016/j.rhum.2022.09.015.</i> <i>[2] Stewart S, et al. Semin Arthritis Rheum. 2019; 49(1):62-73.</i> <i>[3] Christiansen SN, et al. Semin Arthritis Rheum. 2021; 51:644-49.</i> <h3>Acknowledgements</h3> Funded by Carlos III Health Institute (AES PI21/00544), Conselleria de Sanitat (GV/2019/138) and Grunenthal labs. <h3>Disclosure of Interests</h3> María-Luisa Peral: None declared, Silvia Gomez-Sabater: None declared, Rocio Caño-Alameda: None declared, Alejandra Bermúdez-García: None declared, Teresa Lozano: None declared, Ruth Sánchez-Ortiga: None declared, Miguel Perdiguero: None declared, Elena Caro: None declared, Carolina Ruiz: None declared, Rubén Francés: None declared, Eliseo Pascual: None declared, Mariano Andrés Speakers bureau: Menarini, Grant/research support from: Grunenthal.